Tests in biology are moving from the use of a relatively limited number of relatively large samples toward automated mass production tests on a large number of relatively small samples. This results from the simultaneous analysis of a large number of parameters, such as a large number of statistical samples obtained, or a large number of reagents. Some testing being conducted requires a very high number of individual samples, and some sample material is very scarce or very expensive. High density titre plates are currently known which arrange a number of small vessels as desired for the test at hand, with each small vessel containing a small sample. The titre plate is manipulated so as to provide access to the desired sample, or separate means are used to access the desired sample while the titre plate remains stationary. Control of the movement of the plate or the separate access means can be by computer, for the sake of speed and accuracy.
It has been recognized that in some areas, even such high density titre plates will require larger amounts of sample material than will be readily or economically available. It would be desirable, therefore, to be able to conduct testing on an extremely large number of extremely small samples. The desired sample size would be in the range of 0.1 to 50 nanoliters (10.sup.-9 liter). Such minute volumes are frequently called nanovolumes. Previously known titre plates will not efficiently handle such minute volumes, because the sample vessels would make handling of the samples very difficult or impossible. In addition, currently known means of moving a sample from one location to another location for analysis or treatment would be inadequate for the accurate and non-destructive handling of nanovolumes.
It is therefore an object of the present invention to provide a method and apparatus for manipulating a large number of nanovolume samples for analysis or treatment, while conserving the sample material. It is a further object of the present invention to provide a test surface apparatus on which a large number of nanovolume samples can be accurately placed, and on which the samples can be moved about accurately and conservatively, for the purpose of analysis or treatment. It is a still further object of the present invention to provide an apparatus for conservative generation and accurate dispensing of nanovolume samples onto a test surface. It is a yet further object of the present invention to provide an apparatus for accurate and conservative picking up of nanovolume samples from a test surface. It is a still further object of the present invention to provide a method and an apparatus for manipulation of nanovolume samples, which are easy and economical to implement.